Of course they can be let alone with every thing else. However that what i love about anime. It's what gives it's flavor and elegance. It's what makes anime work for me. Also why i enjoy it so much. Their is so many aspects of it and it sometimes hits home with me because their is just so many things that go on. Andddd i lost my train of thought hah. BUt yeah i think they do that to really touch you, and give it some life and funny and all that good stuff

Yes It can easily be overly dramatic, take my favorite anime for example, Eureka Seven, It had loads of time where it was overly dramatic, but I still LOVE it. Anime doesn't have to be like real life, It is like an escape from reality and so I say let the emotions soar!!!

I think this is more a cultural thing than anything. Japanese drama, in general, is much more exaggerated in its emotional content than American drama. Yes, cartoons, by definition, are exaggerated anyway, but my experience with other media says this just tends to be a preference of Japanese people in general. I'm no sociologist, though.